Silent Hill is a very hard, scary, and frustrating game, which makes the last boss obviously hard to kill.

Steps

There are 2 bosses that you face off at the end of the game, which depends on your ending. Here is a list of the final bosses.

Method1

The Child Goddess

1

If you allow Dahlia to successfully complete the ritual, you will get this boss. This boss occurs in the bad ending, which you could get in more than two ways, mostly by using Fire-Arms(Guns instead of melee weapons(Hand held defense items).

2

Equip your rifle, handgun, or shotgun. If you see lightning, either run away or shoot into her chest. Shooting into her chest will cause more damage than regular shots, but it is a good idea to run away.

3

As you escape her wrath, run in zigzagging patterns so the lightning won't reach you. If you get hit, use 1 or 2 NUTRITION RINKS or a FIRST-AID KIT.

4

As you shoot her,notice the gate that surrounds her,you cannot shoot through this, so when shooting shoot at the opening of the gate,(NOTE:This will make it easier to to let her hurt you).

Method2

The Winged Monster

1

You will receive this ending, by ruining the ritual that Dahlia is trying to complete,and killing more enemies with Melee weapons.

2

Equip your RIFLE,and take 10 shots at her.

3

If it doesn't die, equip your SHOTGUN and proceed.

Method3

At the End (Good Ending)

At the end you see the scene 7 years ago, when Harry and his wife find Cheryl, then Allessa will give you a new daughter,(who is actually Heather, the reincarnation of Cheryl and Allessa, who is the main character in Silent Hill 3), and it turns out Harry didn't die in the crash.

Method4

At the End(Bad Ending)

After you are done with the game,you will see several long cut scenes,one of them shows Harry,dead from the car crash.